


It's darkest before dawn

by SennaLaureen



Category: Yu-Gi-Oh! Duel Monsters (Anime & Manga)
Genre: A LOT of Angst, Angst, Don't Like Don't Read, M/M, Pining, Sibling Incest, Unrequited Love, in other words, like really a lot, romantic relationship between siblings
Language: English
Status: In-Progress
Published: 2020-12-01
Updated: 2020-12-29
Packaged: 2021-03-10 01:15:23
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 4,806
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27825880
Author URL: https://archiveofourown.org/users/SennaLaureen/pseuds/SennaLaureen
Summary: Mokuba has a secret, and he is absolutely determined to take it to his grave.
Relationships: Kaiba Mokuba/Kaiba Seto
Comments: 13
Kudos: 16





	1. Chapter 1

**Author's Note:**

  * For [RedScarsHurt](https://archiveofourown.org/users/RedScarsHurt/gifts).



“The future is now: Kaiba Corp. announces that games based entirely on full immersion into a virtual reality are at the final stage of testing and will soon be available to broader public. According to a report from a spokesperson the games’ full immersion into the fictional world is reached by a temporarily amnesia, that allows the gamers to believe they actually experience the story of the game. The process is already perfected and shall be completely safe for…”

With the press of the button Seto Kaiba turned off the TV. In any other situation he’d be furious about the use of the word “amnesia” by the news. Since this word is associated with car crashes more than anything, that will surely saw insecurities in the minds of his customers, not to mention that it was just factually wrong - the process itself is nothing like amnesia. He himself had tested it first, and if there was even a yota of a chance for the process to be a danger to mind or body, he’d never let Mokuba be the official tester of the games the two of them planned to publish. But with what Hinato, the tech department chef, told him an hour ago, he couldn’t care less about the future of this project, even though this was about to become the next big step forward for the Kaiba Corp.

Right now he could not find it in himself to care about anything other than Mokuba.  
  


* * *

  
Hinato was a middle-aged woman with an astonishing career in neurological technologies and an incredible intellect. She was the person behind the upcoming technology of fully immersible games and enjoyed a rock-solid position at the Kaiba Corp. for many years at this point.

All the more surprised was Seto, when Hinato asked for a private meeting and stood in front of his desk, while clutching her notepad a tidbit too hard – the only sign betraying her nervousness.

“I’m listening.” Seto narrowed his gaze on her – Hinato’s agitation already carried over and he was mentally going through the past days trying to determine what could have gone wrong.

“We will need more time testing the games and the tech.”

“You’ll get it.” This was obviously not why she insisted on this tête-à-tête meeting with him instead of sending an email, and Seto was getting impatient. “But I’ll need a detailed report on the reasons why. And the real reason you are here, Hinato.”

She nodded and seemed to have found her center. “Three out of five games are choice-based. The testing for the main paths of the games – with most obvious, mainstream choices – turned out to be faulty so far.”

Since the gamers disconnect from their memories for the duration of the experience, they don’t remember anything about themselves and thus the testers cannot be told to make certain choices – they simply won’t remember having been told that once they are ingame.

Seto needed a split second to connect the dots.

“You mean, Mokuba was not able to make the right choices?” Suddenly Hinato’s nervousness made sense – the issue was his little brother, and his world immediately started shifting in its axes: the company, the tech, the games - everything faded to background noise.

“Yes.” Hinato looked down at her tablet. “I could not put a finger on what was wrong, so I consulted Dr. Tashiro.”

The wrinkled face of the old psychologist resurfaced from Seto’s memories about the earliest stages of development– how he himself tested the tech, and had to suffer Dr. Tashiro’s observations of his mental state far longer than Seto deemed necessary, though he endured the sessions wanting to be absolutely certain that the immersion is safe, before letting Mokuba take over the tests.

_Did he fail?_

_Did he not take something into account before letting his little brother play with unsafe technology?_

While his expression betrayed nothing, there was a storm brewing inside Seto, his mind going a mile a minute.

Hinato pressed something on her tablet. “I just sent you Dr. Tashiro’s report. He asked me to emphasize that he cannot make a clear diagnosis with only the data I provided him, so everything in this report is to be taken with a grain of salt.”

A notification popped up on Seto’s office computer and he opened it, a heavy knot in his stomach.

It was a chart with decisions Mokuba made while testing the game on the left and Dr. Tashiro’s speculations on the right. Seto scanned through the latter.

_deep-seated guilt… unusual readiness to sacrifice himself… low self esteem… signs of being under pressure…_

Each of them felt like a blow to the gut, but the last tore the ground from beneath him.

_Abandonment issues._

For a moment Seto couldn’t think straight.

At the bottom of the report was a post scriptum from Dr. Tashiro:

_‘While it is impossible for me to determine the cause of these issues, they seem to be far older than the start of equipment testing, and therefore could not have been caused directly by the process of immersion, though it is impossible for me to make a clear diagnosis with the provided data only.’_

Seto could not discern whether that made it better or not – on the one hand, he apparently was not directly to blame for having overlooked something while he tested the immersion himself. On the other hand, if what Dr. Tashiro says is true and the issues predate the start of their project, then it’s been years that something was wrong with Mokuba… and Seto never noticed… How is that possible?...

_Was he blind?_

Seto stopped himself from falling down that pit yet. First things first.

“Hinato, the testing of the equipment and the games is postponed indefinitely. You and your team will work together with Dr. Tashiro to once again determine the safety of the tech. He shall appoint a team of independent professionals for this.”

“Understood. This will call for a significant delay in production.” However, Hinato seemed to be satisfied with the instructions, like she expected nothing less from Seto.

“I’d rather delay the project or scrap it altogether than endangering children, Hinato.”

The woman nodded in agreement and bowed. Before she reached the door to Seto’s office, he stopped her in her tracks.

“Do not change the schedule before tomorrow morning and not a single word to Mokuba.”  
  


* * *

  
The younger Kaiba – who officially occupied the position of the Tech Development Lead, while simultaneously overlooking two other KC departments - was absorbed in his laptop, completely oblivious of his big brother standing in the doorway to his office.

Ever since Mokuba returned from his study abroad four years ago and finally signed an official contract with the Kaiba Corp., he was giving his brother’s company all his time, pushing himself to the limit and beyond, neatly filling out all the roles that his older brother needed to be filled in order to meet deadlines and attain perfection of every project. Seto was not surprised - after all, even as a kid Mokuba already worked most of his free time at their company, and the younger Kaiba did not make it a secret that he wanted to continue doing so after he graduates. Mokuba used to joke about how they’ll stay together forever working at the Kaiba Corp. and Seto usually rewarded his little brother with a rare smirk and an even rarer pad on his head, all while trying to conceal how happy that prospect made him.

Now, in context of that Seto learned about Mokuba today, this joke lost all the positive connotations and became both a sinister prophesy and big flashing neon sign that Seto had the obligation to notice, but didn’t.

_Abandonment issues._

How did he not notice? _How?_

Seto absolutely did not know how to start the long overdue conversation. Instead he took in the slim frame of the young man hunched over the computer. Mokuba’s standard grey suit did nothing to hide how unnaturally thin he was. His long black hair was now bound by a hair tie, long strands spreading across shoulders, the bands were hanging low above the eyes. The younger man was unaware of being watched, and now, that Seto knew what to look for, it was like scales falling from his eyes - the tensed line of Mokuba’s shoulders, the corners of his mouth and the violet eyes – all this emanated impalpable sadness.

This young man was a polar opposite of the bold kid full of energy Mokuba used to be. Seto’s heart sank at the realization just how much his little brother changed and for how long did he not bother asking even himself if Mokuba was allright.

Because he obviously wasn’t.

Suddenly he was overwhelmed by a wave of shame - it took Hinato, Dr. Tashiro and a whole project to make him realize that just because his little brother was here and fine, it did not mean Mokuba was happy.

_You failed him._

It hit Seto like a truck, and he had to lean against the wall.

The biggest goal of Seto’s life was protecting his little brother and making him happy, but… when and where did he stop actually looking out for Mokuba and started seeing just the younger’s superficial smile? When was the last time they were together beyond work and occasional dinner at home? When was the last time they spoke about anything other than work?

It took Seto a moment gain the upper hand over all his bubbling emotions. He needed to concentrate in order to bridge the gap that somehow manifested between them, and try to make it up to his little brother for all the time he was apparently blind.

Seto knocked twice on the door and stepped inside.

Mokuba jumped at the sound and turned around. “Hello, Seto!” He beamed at his brother and for a split second Seto saw a younger version of his brother smiling at him like the sun itself. But the vision was gone as quick as it came.

“It’s a good thing you came by, I actually planned to come over and tell you about the test we did yesterday.” With one click Mokuba called up the files on his laptop, under the wrong impression that Seto came by to talk about work.

As if there could not have been any other reason for them to talk, for Seto to come see Mokuba. The older man swallowed a lump in his throat.

“I’m actually not here to talk about the test.” He leaned on the table next to Mokuba and crossed his arms. “I spoke to Hinato – the tests are postponed for now, I want the tech department to take a step back and go through an earlier stage of testing again, just to be sure.”

“What?” Mokuba looked up to his brother, clearly confused and upset. “But we already made it so far! We even announced it on TV! Why would you set the development so far back?”

This wasn’t easy, Seto wasn’t the person to talk about feelings, but there was no way around it – he needed to know what was going on with his brother. “You did not make the necessary mainstream choices while testing. This is actually the reason I wanted to talk to you.”

Mokuba blanched, and Seto knew instantly that he did not approach the subject with the required tactfulness. Shit.

“I- I’m sorry! Let me try again, I just-“ Mokuba jumped to his feet, his eyes wide and pleading, his voice a pitch higher than usual.

_Signs of being under pressure._

“Mokuba…”

“I’ll get it right this time, I promise!...”

“Mokuba!” Seto grabbed the other’s upper arms and pressed slightly in a desperate attempt to make his brother stop. Mokuba let out a surprised gasp, his further attempts at apologizing died out in his throat, big violet eyes anxiously scanned Seto’s face.

“This isn’t your fault. I ordered it because there was a small chance of damage to the psyche of those undergoing the full immersion.”

“What?” The younger Kaiba stared at him disbelievingly.

For a second Seto was tempted to withhold Dr. Tashiro’s evaluations of Mokuba’s state of mind from him and make something up as to why he set the development back, but he could count on one hand all the times he ever lied to Mokuba and he regretted every single one. Besides, lying would be highly hypocritical, given that Seto hoped for his little brother to open up to him and be honest about what was wrong – and he just could not start that with a lie himself.

Seto pulled up a small tablet from his pocket and unlocked it before giving it to Mokuba. The other hastily scanned the report and his eyes went round in surprise, followed by a myriad of conflicting emotions flickering on and off. Seto was carefully watching Mokuba's expression while the younger was reading Dr. Tashiros results more deeply, and he could have sworn that for a second the mask slipped and there was fear written all over Mokuba's face. But it was gone immediately – almost quick enough to make Seto believe it wasn’t there at all - and the young man looked up.

He was furious.

"I did not allow anyone to evaluate my psychological state without my consent or even my knowledge! This is infringement of my privacy! How many people besides Dr. Tashiro know about it?"

Taken aback, Seto did not have time to reconsider his next words: "Hinato was the one who notified Dr. Tashiro..."

"Great! That practically means everyone knows! Fantastic!" The younger man threw the tablet on the table and turned towards the window, fuming. "If that is why you think the technology is unsafe, then you are wrong, and you should have talked to me before calling everything off! I am aware that…”

Absolutely bewildered, Seto listened to Mokuba’s rant, not able to recognize his little brother. But then it dawned on him. 

Mokuba was deliberately diverting the conversation.

“… You need to call Hinato and reinstate the testing, because there is nothing wrong with the technology and…”

“No.” Despite the firm and categorical tone, Seto put as much tenderness in his voice as he could.

Mokuba, who delivered his rant demonstratively looking out of the big window, turned around, eyes wide.

“I’m sorry that Hinato involved Dr. Tashiro and ended up doing something you did not want to be done to you. I’ll talk to her so that something like this does not happen again. I’ll also make sure nobody else sees the report.” Seto paused, desperately hoping that the soft, soothing tone would deliver the message.

“But, Mokuba – why are you feeling this way? _What is going on?_ ”

 _What did I do wrong? How, when and where did I fail you?_ _And how do I make it up to you?_

The wind completely taken out of Mokuba’s sails, the young man suddenly looked like a deer caught in the headlights.

“I don’t want to talk about it! It’s something I’m dealing with on my own, this is none of your business!” The seemingly harsh words lacked any cruelty and, in their barely noticeable shakiness, felt less like lashing out, and more like a desperate attempt at escaping a bear trap that snapped and was about to fall shut.

Right now Mokuba resembled a cornered, frightened animal. Seto has never seen his little brother act like that towards him.

It hurt.

It hurt knowing that Mokuba did not trust Seto enough to confine in him, to share his pain.

What did Seto do or failed to do, that made Mokuba distrust him this much? The realization just how much more serious the situation was than he initially thought, set in slowly and spread in Seto’s veins like poison, leaving acidic taste of anxiety in his mouth – the same crushing anxiety, that always sets in when it’s about Mokuba, only this time he did not have a physical enemy he could defeat, but rather something much more sinister, something Seto couldn’t even name, let alone defeat. And chances were that Seto himself was to blame for this.

At a loss of words once again, Seto made a step towards his brother, instinctively hoping to bridge the gap between them - if not with words, then…

“I’m sorry. I didn’t mean it.” Mokuba’s voice was robotic, void of any emotion, and it made Seto freeze momentarily in place. The younger rushed right past Seto without looking at him and made a beeline for the door. “See you at home, Nii-sama.”

“Wait! Mokuba!…” The younger already disappeared down the corridor, and Seto was about to run after him, but stopped at the door.

The way his brother’s last words just… fell to the floor like stones… almost as if Mokuba was this close to a breaking point, barely holding himself together…

Seto closed the door to Mokuba’s office and leaned with his back against the wood. He understood absolutely nothing on the conscious level, but his instincts in regards to his brother, the instincts he was been sharpening almost all his life, told him to give Mokuba space right now. 

The last thing Seto wanted was for Mokuba to break.


	2. Chapter 2

**Summary for the Chapter:**

> He didn't remember the exact moment his feelings towards his brother changed - no, it felt more like a natural progression of his love for Seto he always harbored. In that sense, he always loved Seto much deeper than a normal brother would – after all, nothing in their lives was ever normal.

**Notes for the Chapter:**

> First of all, thank you to everyone who reads, leaves comments and/or kudos! I'm glad you are here!
> 
> If you thought the first chapter was angsty, you should buckle up - this chapter covers Mokuba's POV! ^.^°

People in the corridor hastily made way for him, their curious gazes went unnoticed as Mokuba rushed towards the door to the emergency stairwell. His footsteps echoed in the long shaft for three floors until he finally realized he wasn’t being followed. Leaning against the railing, he tried desperately to fight the impending panic attack.

Seto caught him completely off guard and confronted him with all that Mokuba never wanted anyone - and the least of all Seto! - to know. He thought he was hiding it all well enough – turns out it only took a video game test and a superficial analysis of a psychologist to bring it all to light.

_What happens if Dr. Tashiro digs a little deeper?..._

Mokuba gasped for air as he couldn’t fight the panic attack any longer.  
  


* * *

  
He didn't remember the exact moment his feelings towards his brother changed - no, it felt more like a natural progression of his love for Seto he always harbored. In that sense, he always loved Seto much deeper than a normal brother would – after all, nothing in their lives was ever normal. It wasn’t normal that Seto had to give up so much for him, while still being a child himself. It wasn’t normal that they only had each other, could only trust each other in the hostile environment of the old Kaiba Corp., until they became unable to trust virtually anyone else, even after Gozaburo and the Big Five were gone. It wasn’t normal, that roughly a decade later, they still only had each other, even though the opportunities for bringing others into their lives presented themselves more than once. It wasn’t normal that they still lived together, just the two of them, in the massive Kaiba villa and their company, and neither of them felt the need to change the way their lives were deeply intertwined, the way they worked like a well-oiled machine, a team of two nothing and no one could tear apart.

It wasn’t normal, that all Mokuba ever really wanted to do was to be there for Seto, to be at his brother’s side, doing that Seto needed from him – and in return, being able to continue sharing his life with Seto.

That's why Mokuba’s feelings towards his brother, that were always there and just evolved when he hit puberty, didn’t strike him as anything unusual – he still wanted to spend the rest of his life with Seto, still wanted to repay Seto for everything his older brother did for him and was still doing, still wanted to protect Seto the same way Seto protected him. He still wanted nothing more than to see his older brother happy – all this didn’t change, only increased tenfold now, that Mokuba was been more actively working towards getting his degree and towards a contract with the Kaiba Corp., so that he could remain at Seto’s side in all aspects of life. It was only when fifteen year old Mokuba woke up from an erotic dream that involved Seto, did he realize that his innocent love for his brother blossomed into a full-blown adult love, including sexual desire.

This was the moment he realized he has been in love with Seto for a very long time already, and this love has now been merely completed. 

Of course, he examined it thoroughly, in hopes that the newly-discovered sexual desire towards his brother was just a misguided pubertal thing. Once that proved to be wrong, Mokuba tried to get it out of his system – his first and only long-time boyfriend was a tall senior year boy from his school. Neither this one-year-long relationship nor the following one-night stands with men and women – who often had blue eyes and hazelnut-brown hair – proved to be effective. None of these people meant anything to Mokuba – the love he felt for Seto was of a whole different nature than anyone else could ever give him. At some point after he returned from his time abroad at twenty-two, Mokuba resigned and stopped trying to change who he loved – he came to terms with the fact that his feelings for Seto were an integral part of him and would most likely remain a part of him until he died, and he finally found himself at peace as soon as he stopped trying to turn himself inside out to get that was perceived as disgusting out of his heart, especially since he never felt like whole-heartedly loving Seto with every fiber of his being was disgusting or unnatural or wrong – no, for Mokuba, deep down, on an emotional level, it felt _right_.

On a rational level, of course, he knew very well that society condemned feelings like these as wrong for many good reasons and that’s why Mokuba put on a mask the moment he comprehended the whole extent of his love for Seto, and never once put it down again. And behind that mask, he was _terrified_.

Terrified of Seto turning away from him with disgust on his face if he ever found out.

Mokuba, as much as he was an optimist, never deluded himself – there was absolutely no chance of Seto reciprocating his feelings. No, Seto would be disgusted, if he ever found out that Mokuba loved him more than just as a brother, and Mokuba couldn’t even blame him! Finding out that your own brother - your only family! - harbored such feelings would certainly be a shock, and disgust would be a natural response, entirely expected and in no way unreasonable. Mokuba deliberately did not allow himself to think that he might do Seto injustice by predicting his reaction to be as grievous as that – he absolutely denied himself even a sliver of hope that Seto might be… understanding or even accepting. Forgiving. As long as there was a real, solid chance that he would lose Seto and hurt him if he ever revealed the true nature of his love, he could not allow himself to hope for a better outcome, because hope was dangerous. Even the tiniest bit of it grew in one’s heart unnoticed until he was swayed to change his mind and ended up destroying everything good that was between him and Seto. Mokuba did not dare to hope – the risk was too big.

Besides, the chance of Seto being understanding of _that_ was... small. Far too small compared to the real possibility of him being disgusted, of him wanting Mokuba gone from his life.

Mokuba drew in a shaky breath – it felt like his chest was being cut open at the mere thought of Seto turning away from him. 

_Please, don’t leave me! I’ll do anything you want, I’ll become anyone you need, just… please, don’t leave me!_

He couldn’t _ever_ let Seto or anyone else know how he felt. If his feelings came to light, he’d not only lose Seto – Seto would also lose him, whom he undoubtedly loved as well, just not in the same fucked up way Mokuba did. He couldn’t do that to Seto – his brother was not to blame for Mokuba’s misguided feelings.

No, he had to keep this side of him a secret at all costs. It was more than enough for Mokuba to remain at Seto’s side as his brother, and he hoped until now, that he’d managed just fine with that mask glued to his face for years – and yet just now Seto turned up in his office with a half-solved puzzle, and a concerned expression, begging him to tell why he was afraid to lose Seto, why he was putting himself under as much pressure working for Seto at their company.

The answer to the latter was entirely emotional and beyond any logic: it was Mokuba’s subconscious hope that if Seto ever found out about his feelings, he would allow Mokuba to keep, if not his residence at the Kaiba villa, then at least his place in the corporation, and thus still be somewhat near Seto. And then Mokuba had at least a chance to prove to his brother that he needed not be concerned with that Mokuba couldn’t help feeling, that Mokuba would never act on his feelings, would never make it an issue!...

Mokuba knew that it was utterly irrational – if Seto ever were to find out, he wouldn’t care about the importance of the work Mokuba was doing for the company, or his promises to never act on his perversions. None of his achievements or his promises would mean anything in the face of…

Incest. Even the word itself was _ugly_ , radiating foul stench, belonging to the darkest depths of human nature. And it was so far removed from what Mokuba felt deep inside whenever he thought about Seto – light, warmth, hope and happiness. Love. How could those two be the same?...  
  


* * *

  
The cold air of the emergency stairway leading all the way from the top of the KC tower to the underground carpark dried Mokuba’s face on its way down. He didn’t know how long he was sitting there, with his back to the metal railing – the subsiding panic attack took a toll on him, his hands were still trembling, but the sense of duty urged him to stand up and… what? He couldn’t go back to his office, not with that face, and he absolutely could not confront Seto right now, but he had to get back to work – two projects were waiting for his evaluation, and the deadline was tomorrow. After he so pathetically failed at testing the games, wasted everyone’s time, and on top of everything made Seto set the development of the new games back for nothing, Mokuba just couldn’t allow himself to neglect his duties. Hopefully he’d get his home computer to connect to the company network.

And all that while he had to come up with a way to perform damage control to prevent his life from falling apart - to stop Seto from digging deeper before his genius brother connected the dots.

When Mokuba arrived at the carpark, he was fully composed again. He signaled one of the drivers on call and told him to bring him to the Kaiba residence.

Trees and city lights passing by had a calming effect, lulling him to sleep to regain the energy lost to the panic attack, but Mokuba refused. Instead, he fished his phone out to check his emails – the only thing he could do until he arrived home.

After a moment of scrolling and reading, and scrolling again, he furrowed his brow – the two projects he ought to work on were postponed until the day after tomorrow – the first because the department head just now realized he was unable to deliver his part of the project to Mokuba until then, and the second because the tech department made a mistake and deleted some important files, and now they needed time to recover them... Mokuba frowned, only to press his hand to his mouth in realization.

Seto.

It was Seto’s doing. He was deliberately delaying the preliminary work for both projects, so that Mokuba didn’t have to work on them today or even tomorrow.

A tear drop hit the phone screen and Mokuba briefly wondered where it came from, until he realized he was crying. The letters on the small screen blurred into his brother’s beloved features, warm and reassuring half-smile reserved only for Mokuba made it incredibly hard to believe that this same face could ever turn away from him in disgust. Instead Mokuba could swear he heard his brother’s voice.

_Everything will be fine._

For a brief blissful moment he allowed himself to believe it.


End file.
